Concrete bridge construction.



H. L. PEGRAM.

CONCRETE BRIDGE comsmucnow.

APPLICATION FILED JULY 9.1915.

Patented May 8, 1917.

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A TTORNE Y5 H. L. PEGRAM.

CONCRETE BRIDGE CONSTRUCHON.

APPLICATION FiLED JULY 9. i915.

Patented Mary 8, 1917.

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CONCRETE BRIDGE CONSTRUCTION.

APPLICATION FILED JULY 9.1915.

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H. L. PEGRAM.

CONCRETE BRIDGE CONSTRUCTIQN.

APPLICATION FILED JULY 9| 1915- 1,Q25,%5 Patented May 8, 1917.

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Patehted May 8,1917.

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APPUCATION FILED IULY 9,1915- L fi fin Patented May 8, 1917 6 EEEEEEEEEEEE 6- WITNESSES i a/gzm y HCWARD LEONZO PEGRAM, 0F MULVANE, KANSAS.

CONCRETE BRIDGE CONSTRUCTION.

Specification of Letters Patent.

Patented May 8', 161?.

Application filed July 9, 1915. Serial No. 38,878.

To all whom it may concern:

Be it known that I, HOWARD L. PEGRAM, a citizen of the United States, and a resident of Mulvane, in the county of Mulvane and State of Kansas, have invented certain new and useful Improvements in Concrete Bridge Construction, of which the following is a specification.

My invention relates to means for building reinforced concrete bridges, and the main object thereof is to provide a system of reinforcing which also carries the load of the bridge, including the concrete, in separate truss formation, together with the mold, ready for pouring the concrete.

A further object is to provide anchoring means for the bridge well back of the water line and at a considerably lower level than the top of the bridge, the skeleton or framework being self-supporting previous to the pouring of the concrete.

Another object is to provide such a preliminary structure that the completed bridge will be of relatively great strength although the weight and Cost thereof is relatively low.

My invention is fully described in the following specification, of which the accompanying drawings form a part, in which like characters refer to like parts in each of the views, and in which Figure 1 is a longitudinal, central, vertical, section through the preliminary structure of a bridge constructed in accordance with my invention, no concrete being shown except for the foundations and piers;

Fig. 2 is a similar view of the completed bridge, with my form removed;

Fig. 3 is a transverse section taken through the bridge after the concrete has been completed but previous to removing my mold, on the line 3-8 of Fig. 1;

Fig. 4 is a fragmentary plan view of the structure at one end of the bridge, not including the reinforcing and concrete supporting rods;

Fig. 5 is a detached view of one of the anchoring yokes which I employ at each end of the bridge;

Fig. 6 is a similar View of another anchorin% yoke;

g. 7 is a fragmentary plan view of the bottom of the mold, from the upper side thereof, partly broken away at the end;

Fig. 8 is a perspective view of one of the side plates of the mold; and

Fig. 9 is a similar view of one of the end plates of the mold.

In practice, I first form the foundations 10 of concrete or any other suitable material and build the abutments or piers l1 thereon into each of which have been set two of the yokes 12 shown in Fig. 6, suitably spaced, and one of the yokes 13 shown in Fig. 5 therebetween, the former being lower than the latter and extended farther back from the stream or water line. The piers 11 are joined by means of a web 14 on the stream side of said piers, on each side of the stream, shown most clearly in Figs. 2 and 4:.

Stretched across the tops of all of the yokes 12 at each side of the bridged stream is a bar 15, another bar being similarly stretched across the shoreward ends of said yokes as shown at 16, suitable loops being provided in the yokes 12 to receive the bars, and when in positions shown, these bars may be tied in place in any suitable and temporary manner.

Similarly restin upon the tops of all the yokes 13 at each si e of the stream is a transverse bar 17, suitable loops being provided for receiving the same, and these may also be temporarily tied in position if desired.

The bridge is intended to be of multiple truss form, a pier being provided at each side of the stream for each truss, five piers being illustrated in Fig. 4 and five trusses in Fig. 3, but any number thereof may be employed according to the desired width of the bridge.

From the bar 16 at one side of the stream I pass a plurality of relatively light rods 18 downwardly at an incline to the top of the respective piers where they are tied by bars 19 and 20, thence across the stream to the corresponding pier where similar tie bars are employed, and thence to the other bar 16, these rods being supported in arch formation by means of stays 21 leading from the respective bars 16 to said rods over the bars 15, these rods 18 being shown three in number over each of the sets of piers, one

pier at each side of the stream constituting a set.

Stretched directly from one bar 16 to the other are a plurality of rods 22, being shown as two in number for each set of piers or, in other words, for each truss, and stretched from the bar 16 on one side of the stream to the bar 16 on the other is a plurality of rods 23 passed over the bars 15, these last named rods being festooned and tied to the rods 18 and 22 at the center of the structure, and being shown as three in number for each truss.

Stretched between the bars 16 and led over the bars 17 are a plurality of rods 24 equidistant from each other for the proposed width of the bridge, these being taut and carrying a plurality of spaced rods 25 to form the floor reinforcing, and I also provide similar rods 26 resting on the rods 18 and 23 and which may be temporarily tied thereto.

With the exception of the rods 2 1 all of the rods spanning the stream are in sets, one for each proposed truss, and, because of the supporting power of these rods, particularly the rods 23, a very light and strong preliminary structure results, and a very strong and light bridge when completed.

The arch of the proposed bridge is formed by means of an arched mold plate 27 formed in longitudinal sections joined by means of angle-iron strips 28 and having spaces 29 cut out therefrom, several of which are shown in Fig. 7, and each of these cut outs is framed, on the upper surface of the plate 27, by means of angle-iron strips 30 adapted to be bolted to core members 31 and 32 consisting of shells open at their lower sides to encompass the respective frames 30, as is clearly shown in Fig. 3. The lower edges of these core members are fitted to the plate 27 in order to have their tops all in the same horizontal plane, and said shells or core members are curved or arched in transverse section, as shown in Fig. 3.

Resting between the piers 11 are core members 33 shown in plan in Fig. 7 and in side elevation in Fig. 1, these also being preferably arched, and having shoreward ends upwardly inclined to a point just beneath the bars 16 and slightly shoreward thereof.

Resting against the shoreward faces of these core members 33, on each shore, is an upwardly and shorewardly inclined plate 34; provided with angle-iron strips 35, and resting on the tops of these plates 34 are upwardly and streamwardly inclined plates 36'having angle-iron strips 37 thereon.

Secured to the ends of the plates 34 and 36, at both ends of the structure, are side plates 38, shown in Fig. 8, also provided with angle-iron strips 39, the structure of the plates 34 and 36 being shown in Fig. 9; all of these plates may be made of sections bolted together by means of the angle-iron strips thereon, as may also the end and side plates be so bolted together, the intent being to vmake a unit thereof.

The bottom plate 27 rests upon plates &0 held against the webs 14 and held by means of brace members 11 which may also support brace members 42 for the said bottom plate 27, thus producing a strongly supported casing open at its top for the reception of concrete which may be poured thereinto to inclose all of the yokes, rods, and bars, shown and described, and having a floor formed at the top thereof as indicated by the broken line, Fig. 1.

When the concrete is hard, the side and end plates maybe unbolted from each other, the plates 40 and brace members 41 and 12 may be removed, and the bottom member 27 with its'conneoted cores 31 and 32 dropped out of the concrete and removed, either bodily or in sections, according to the size of the bridge. The end cores, 33 may now be removed, and the finished bridge stands revealed with the reinforcing concealed entirely therein.

The approaches are upwardly inclined toward the floor of the bridge, and earth may be filled in at the bridge'ends to grade the approaches. The spaces formed by the cores 31, 32, and 33, do not weaken the structure, and they do greatly lighten the same and materially reduce the cost of bridge building by the saving of concrete at unimportant points, and it will be noted that the multiple truss form is thus made apparent to all observers.

It is my intent to provide the mold plates, cores, yokes, and bar and rod formation as an entirety, together with the braces shown, in various sizes, although I will construct special sizes to meet conditions as they arise.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a bridge, a plurality of truss elements comprising, each, an upper hammocked set of rods, a horizontal set of rods, a lower arched set of rods, means for tying the same'together at the center of the bridge, means for anchoring the ends thereof, and a concrete inclosure therefor.

2. In a bridge, a plurality of piers at each bridge end, vertically arranged yokes secured to the respective piers, bars carried by said yokes, and a plurality of truss elements comprising, each, an upper hammock-ed set of rods, a horizontal set of rods, and "a lower arched set of rods carried by said bars, and a concrete inclosure therefor.

3. In a bridge, a plurality of piers at each bridge end, vertically arranged yokes semasses cured to the respective piers, bars carried by In testimony whereof I have signed my said yokes, a set 01' upper hammocked rods name to thls speclficatlon 1n the presence of over each pan of plers, a set of horlzontal two subscrlblng Witnesses.

rods 'thereover, a set of arched rods there- HOWARD LEONZO PEGRAM. over, said rods being carried by said bars, Witnesses:

stays from certain of said bars to said arched ORIE GATHGART,

rods, and a concrete incl-osure therefor. S. W. WRIGHT.

opies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. U. 

